Our invention relates to an apparatus for reading and/or writing information with magnetic recording media such as, typically, a flexible magnetic disk now generally referred to as a floppy disk. More particularly, our invention pertains to such a magnetic data transfer apparatus, or a floppy disk drive according to common parlance, having one or two magnetic transducer head assemblies of improved coil arrangement with respect to their supporting means.
A typical prior art floppy disk drive comparable to that of our present invention is disclosed in Noda U.S. patent application Ser. No. 434,400 (corresponding to Japanese Laid Open Patent Application No. 58-77080 dated May 10, 1983) filed Oct. 14, 1982 and assigned to the assignee of the instant application, now U.S. Pat. No. 4,602,306. Intended for use with a double sided floppy disk, that known disk drive has a pair of magnetic transducer head assemblies, one mounted directly on a carriage movable radially of the floppy disk, and the other mounted on a load arm pivoted on the carriage. This prior application also suggests the mounting of the head assemblies on the carriage and the load arm via respective flexure seats but contains no teaching whatever as to the arrangement of the coils included in the head assemblies.
As far as we are aware, however, Castrodale et al. U.S. Pat. No. 4,089,029 reflects typical conventional transducer coil arrangement. According to this patent the transducer coils are disposed on the magnetic core portions protruding on those sides of the flexure seats which are directed away from the floppy disk. The known constructions of the head assemblies have necessitated this coil arrangement for the ease of their assemblage and mounting.
The gapped surfaces of the head assemblies must be disposed a sufficient distance away from their flexure seats to avoid contact of the floppy disk, which is subject to wobbling motion during rotation, with the head carrying means. Accordingly, the conventional arrangement of the coils on those sides of the head seats away from the disk makes still greater the dimensions of the magnetic cores in a direction perpendicular to the disk, necessitating a corresponding increase in the dimension of the complete disk drive in the same direction. We also object to such elongate magnetic cores because of unnecessarily great magnetic losses and, in consequence, of low data transducing efficiencies.